Does your car let you down every time you try to start it, or those
wipers only work when it is not raining? Perhaps the indicators go dim
every time you apply the brakes, and the horn only operates when the
lights are off.
Before you go out to buy new lights, horns, switch gear, voltage
rectifiers and anything else that carries an electrical current, it may
be worthwhile spending time checking out the wiring rather than
shelling out on new parts.
Quite often I have found that electrical components supposedly
faulty, are perfectly all right, i.e., "blown" headlamps which are
intact, switches that work when connected to a multi-tester, horns that
stop making funny gurgling noises and operate correctly when connected
to the battery for a test.
Many electrical faults are caused by two frequently overlooked
factors, either working separately, or together to produce a variety of
interesting visual and sometimes pyrotechnic effects. The first of
these factors is simply caused by age and the climate -
electro-rheumatism if you like. The second is caused by that stalwart
of the motoring world, Captain Accessory!
I am always surprised by the large number of good quality products
on the market (and this does include radios, etc.) which are let down
either by the cheap, easy-to-use connectors sold with the kit, or by
"hash wiring" on the part of the installer. Fitting any accessory
should be dealt with in the same way that any other task should be
undertaken on a vehicle - properly. Connections should be mechanically
and electrically sound.
The worst electrical problems I have faced have been caused by
"bodged" wiring or faulty connections. Easy-to-use connectors often
provide me with hours of entertainment, as does unwrapping electrical
insulation tape to find wires that have been just cut, stripped back
and twisted together. It always works for a while!
And it's not bodged wiring - some products are of an appalling
quality. For example, I have tried various different HT leads in my car
to "improve the quality of the spark", "reduce resistance", and
"provide better ignition". Moss of these leads have been useless. It
doesn't matter two hoots that the PTFE casing and superior ‰ quality
copper core offers less resistance than the normal standard item - what
matters is that if the cap doesn't fit the spark plug, it will just
bounce off. One famous make had such appalling connections that it
would not fit into the standard Lucas distributor.
If you are going to tackle any electrical work for your car, then
do it properly and do it once. Throw away those cheap connectors ad get
the right tools to do the job properly - because I can guarantee that
if you don't, that one day you'll wish you had - or even worse, you'll
get rid of the car because it keeps going wrong. (I've picked up a few
cheap cars like that which sing after two or three house with a
soldering iron!)
Get the Right Tools:
1. Soldering Iron - Get one with: 5 to 15 watts output, stay clean
tips, decent stand, and PTFE leads (which make the iron easy to handle.
2. You probably already own one of those multi-purpose devices
that cuts, strips wires and fits connectors. Throw it in the trash. Buy
instead: Long Nose Pliers, Side Cutters, Wire Strippers, Insulation
Tape, and Solder (60 - 40 lead/tin mix with flux incorporated).
3. Connectors - Get the type of connectors that are already in use
on your car - spade connectors and bullet connectors (that can be
soldered) and throw the crimp connectors into a bin!
Three important safety tips:
1. Disconnect the Battery
A fully charged battery can use around 120 amps to turn over a cold
car engine. Making a mistake and accidentally connecting the positive
to the earth can have some interesting affects, i.e.:
i. Any wire involved in a direct connection will act like a fuse and melt (this includes HT wire).
ii. The battery could explode if an HT wire does not fuse quickly enough.
iii. 120 amps is enough to weld your screwdriver to any object very easily.
iv. You can receive nasty burns if you use yourself as a suitable
earthing point. (Remember DC current differs from AC in that it does
not change direction - once you get to grips with DC it won't let go!)
2. Holding the soldering iron
Never grab the soldering iron if it starts to fall. Sounds obvious,
but there are still plenty of electrical engineers around who hold out
their left hand when greeting somebody!
3. Suitable wiring
Finally, make sure that the wires you are using have the correct
current capacity for the power they have to take. Using cable that is
too thin is the electrical equivalent of reducing three lanes of motor
way into one - total breakdown - if the current is much higher than the
wire, the wire will act like a fuse and melt.
Making Connections
1. Spade connectors
Strip back 1/4" of wire without ripping out half of the strands,
(if you have never used wire strippers before, have plenty of practice
with some old bits of wire) twist the strands together and solder the
bare end.
Always heat the wire with the soldering iron and apply the solder
to the wire while it is still in contact with the iron. The wire must
be hot enough for the solder to flow into the wire strands - but don't
keep the iron there for too long, otherwise the outer sleeve of the
wire will melt back. It is an art worth learning.
Do not apply solder to the iron and then try to "blob" the solder
on to the wire - it never works because the solder "dries out" as the
flux evaporates, and then the resulting joint can become brittle and
prone to breaking (aka "Dry Joint").
Once cool, fit a spade connector sheath over the wire and then
crimp the connector to the wire as shown in the diagram The crimping
makes a mechanically sound connection, but this is not enough.
Returning to the soldering iron, you then need to apply heat to solder
the wire to the connector to ensure an enduring connection, just like
they do at the factory.
2. Bullet connectors
Bullet connectors are needed where (A) two separate lengths of wire
are to be joined together or (B) where an extra wire is to be added to
a main feed.
Many bullet connectors can be crimped on as well as soldered to
enhance the quality of their connection, but the stock items used by BL
tend to be a bit more tricky and can only be soldered - so you must
ensure that the soldered connection is not dry!
Strip back 3/8" of cable and solder the strands. Insert in the end
of the bullet - it may help to "kink" the strands slightly to keep the
bullet in place - and then re-apply the soldering iron to the top of
the bullet. Allow it to heat up and then apply the solder through the
hole at the top of the bullet so that it can run inside, attaching the
cable to the wall of the connector.‰
The advantage of these connectors is that, if corroded, the
connector block can be thrown away and a new one fitted without having
to do any more soldering. Also, they can provide multiple outlets for
power, but watch out for that current overload on the original feed
wire!
The disadvantage is that the connector is a mechanical fit and
prone to electrical failure when corroded, which is why many cars start
going wrong after five year's use!
An Extra Fuse Box
If you are accessory mad, the use of a fuse box with a direct link
to the solenoid may provide a safe, efficient answer, rather than
connecting countless new wires onto an overburdened wire feed.
Again, make sure that the wire, from the feed to the box has
sufficient capacity to deal with any load place upon it (an in-line
fuse may further protect the entire system).
Is it worth the effort you might ask? Yes! A clean job is a good job!
1. If it's soldered, then the connections will be better, stopping
niggling electrical failures and dangerous burn-outs; the connectors
are cheaper too.
2. The proper connectors often allow easier access for repair of equipment.
3. Stops wires from sparking and equipment lasts longer.
4. It looks better, too!
Grahame Bristow
Working on automobiles is inherently dangerous. Moss Motors, Ltd. is not liable for injury or damage due to incorrect installation or use of their products. All products are sold with the understanding that the safe and proper installation and use of the products is the customer’s responsibility. Follow factory workshop manual procedures and instructions, but use current shop safety standards and common sense. Some tasks will require professional advice or services which Moss Motors cannot provide.Email (for Moss Tech help):
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